Analyze f(x)=x3−xf(x) = x^3 - xf(x)=x3−x. Where is it positive?
x∈(−1,0)∪(1,∞)x \in (-1, 0) \cup (1, \infty)x∈(−1,0)∪(1,∞)
x∈(0,1)x \in (0, 1)x∈(0,1)
x>0x > 0x>0
x∈(−∞,0)x \in (-\infty, 0)x∈(−∞,0)